Nanostructure formation of Cu/Si(100) thin film induced by ion beam bombardment

A simple method for fabricating self-organized Cu nano-dots on Si(100) substrate by low energy Ar+ ion beam bombardment of a Cu thin film at room temperature over a large area is demonstrated. The morphological evolution has been investigated using scanning electron microscopy and atomic force microscopy. It was found that nano-ripple patterns formed on a Cu grain surface on a 110 nm thick polycrystalline Cu thin film under normal ion incidence. Uniformly distributed Cu nano-dots were obtained by bombardment of 55 nm thick nano-crystalline Cu thin films. The formation mechanism of the Cu nanostructures was discussed with the aid of numerical simulations using a modified damped Kuramoto–Sivashinsky equation.